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MG MGB Technical - 2 questions?

Hello again,
was wondering about two things?? I have a 1973 B roadster with 55,ooo miles on it. We have recently had some extremely hot weather and my oil pressure has dipped to about 25 when I am at about 1200rpm (idle). Typically when the car is cold I have about 75. Should I be concerned or is this normal to go this low in extremely hot weather? Car seems to be running about half way between the N and the H on the gage (a little warmer than it usually runs) and I am using castrol GTX 20-50.
The other thing is I am thinking of recovering my seats with cloth (Damn Vinyl is a killer in this heat Ha! Ha!) will the later model seat covers say from a 77 fit my seat foams correctly or do they make replacement cloth seats are are decent for a 73??
Thanks in advance
Bud
Bud beck

The oil pressure sounds ok bud. I have a 73 and I get 20-25 at idle here in Ga and its very hot. I'd be more worried about your temp gauge though. Mine stays at normal or very close to it. Is your temp going up on the highways, or at idle, or all the time in hot weather? The engine running hotter will definatelly thin the oil thus bringing the pressure down. I don't know what kind of driving your doing, but if the gauge is that high with normal driving I imagine a long steep hill or being stuck in traffic may pull it even higher.
J Arthurs

Hello J.A.
Boy that was quick... actually my car always ran between the L and N just under normal most of the time... I noticed this summer that it has climbed a bit and runs usually at normal on the highway and rises a bit to half way between N and H when I am in city traffic...
The only thing I have changed is that I have added a badge bar and a set of 5 1/2 inch fog lights in front of the grill do you think its possible that it could have restricted enough air flow to cause that change??????? thank you for such a quick reply..
Bud
Bud beck

Oil pressure should be about 20psi at warm idle and between 50-70psi under load.

Many cars vary from this and it can be for a variety of reasons so dont worry too much of your is different.

Is your oil new?? I have noticed a tendency for my oil pressure to stay high even at warm idle when recently changed, but after a few hundred miles drops to 20 psi as above. At cold idle the oil pressure will stay high, usually at or around what your engine holds under load when warm...

I would check your coolant mixture and if in doubt replace with 50:50 water/coolant as your temp seems a bit high...

~PHIL
Phil

The GT seat coverings will fit - you just have to be more careful about rain than with the "solid" vinyl roadster covers. The seat foams don't dry out too easily.

Wayne
Wayne Pearson

Yes! Two 5.5inch fogs in front of the grille could restirct airflow considerably.

I havent a ruler to hand at present to measure the grille of my MG but i would suggest that as a rough figure you would have reduced the cross sectional grille area by between one third and a half by placing two of these lights in this area.

Assuming you havent got anything such as louvres in the bonnet your car will draw most of it from the grille area so by restricting this area the fan cannot draw as much air through the grille to distribute around the engine bay.

You could try an electric cooling fan which will cut in as temp rises, as the standard belt driven fan is not good in traffic because it is not spinning fast enough with the engine idling.

Alternatively some sort of induction piping to draw the air from somewhere other than the grille could be used, or move the fogs and see what difference it makes.

My comment about checking coolant still holds though and while your there a radiator flush might go down well too, if you spot a bit of gunk inside when you take the filler cap off.

~PHIL
Phil

I rebuilt the seats in my '73 about 10 years ago with the Moss leather seat kit (NOT the grossly expensive VB interior kit). These go on sale sometimes and are worth the effort and cost. They wear great (leather nice and thick and dyed thru).

One of the things I definitely noticed is that the car 'feels' almost 10 degrees cooler in the summer with the leather. And I definitely remember how hot the vinyl seats were in New Orleans!!!

I chose to save my nickels for the leather because I felt that I would have the car long enough ot warrant the cost. Also the cloth WILL rot eventually.

The kit from Moss also seems to absolutely not mind getting a little wet. I haven't let the car sit in a blinding rain storm but I have been caught out with no bad effects.

I recommend the leather if you are going to have the car fo a while.

If you do rebuild the seats, do not forget to buy seat foams AND the diphragm rubber replacements in the bottom. You will be amazed that your butt no longer sits on the floor!
Richard Smith

Think Phil's on track here bud. I would try removing the fog lamps temporarily and see how the temp/oil pressure goes. I think I know the fog lamps you are talking about. The round ones that sit on a inch long stalk? I don't see anywhere else you could put them, as I think they look good in front of the grill too. If the problem dissapears with them removed, I would try an additional fan. This will help in the city, but will have no effect on the highway. You might as well change the thermostat and flush the system and check the hoses while you at it. Remember to open the heater valve. The only other suggestion I would make would be too remove them, but seeing how you just bought them I guess that is probibally a mood point.
J Arthurs

Hello,
Well thank all of you for your solutions I will try refreshing my fluid and cooling system first if it doesnt make much change I will add a fan (I really like those lights Ha! Ha!) and I guess I wont have to worry about the oil pressure to much ... just seemed a bit of a large range....
Thank you all again
Bud,...
bud beck

Bud;
The posts above have pretty well covered the oil & temperature issues. As far as the hot seats go, I have been using synthetic sheepskin seat covers over my vinyl seats for years for this reason, even though the seats are inpretty good condition. I find them at Drug Mart, or Wal Mart every so often for about $15 each.Mine are cream color in a Autumn leaf interior. I have seen them in light to medium grey also. I take them off every fall and throw them in the washer & dryer to clean. They'll last about 5-7 years, then start getting threadbare in places.The only downside is they leave fuzz on the carpeting when newer.
Pete Haburt 76B
Pete Haburt

Bud,

I love Richards idea about the leather option for your seat covers. If you can't afford the leather the cloth seat covers for the 74 GT will fit perfectly and look original. I got mine from the Proper MG, they are the original ones made in the U.K. and not some Taiwan special.

Andy
Andy Preston

This thread was discussed between 23/07/2002 and 27/07/2002

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